1. Field of the Invention
The present invention relates to a swather mounting structure for attaching an elongated swather head to a tractor, and more particularly, to a structure for mounting a swather head on a tractor of the bi-directional type for swathing as the tractor travels in one direction and for drawing the swather in a trailing transport mode when the tractor is driven in the opposite direction.
2. Description of the Prior Art
Swathers and other mower type machines were for a number of years normally designed to be drawn behind conventional farm tractors. There has also been developed combines which are, of course, self-propelled and have either a mower or pick-up head. Swathing machines are also available which may include one or more swathing heads and are self-propelled, such as of the type shown in applicant's Canadian Patent No. 1,183,355, granted Mar. 5, 1985. While large swathing machines of the type shown in applicant's Canadian Patent are preferable for custom operators or for very large agricultural operations, there is still a significant requirement for swathers, which may harvest a considerably narrower swath per pass, but are less expensive and can be used with the conventional tractor used for other purposes on farms. Accordingly, there have been developed swathers which include a structure permitting one or more swather heads to be mounted directly on the tractor, such an arrangement having characteristics which allow for more efficient handling than the older tractor drawn type. The tractor mounted structures have also permitted development of swathers which include more than one head so has to provide a wider swath and include features which allow at least one of the heads to be maneuvered to a transport position. In such a position, the equipment has less width than when in the normal swathing condition so that road travel is possible. Tractor mounted structures of this type are shown in U.S. Pat. No. 4,658,572, issued Apr. 21, 1987, and U.S. Pat. No. 4,768,334, issued Sept. 6, 1988, both granted to Gregory J. Honey and Glenn R. Honey, and assigned to the present assignee, and Canadian Patent No. 1,210,936, granted Sept. 9, 1986, and also assigned to the present assignee.
Tractors of the bi-directional type are now preferred by many farmers, at least for some operations, the most common of such bi-directional tractors being of a centre articulation design, wherein the operators cab is at one end and includes a swivel platform to permit the operator's seat and all of the surrounding control mechanisms to assume two oppositely facing positions. In this type of tractor, the power unit is at the other end on the opposite side of the centre articulation. Although some swather mounting structures have been developed for use in attaching swather heads directly on bi-direction tractors, because of the different driving characteristics, operating features comparable to those experienced on conventional tractors have not been readily achieved.
Moreover, in swathing crops it is preferable to have the option of laying the windrow in different locations behind the swather head, and accordingly, it is common for the transverse conveyor on the swather table behind the sickle bar to have drive means which allows it to travel in either direction, or to be even made up of two or three sections, the drives of which are individually controlled so as to deliver two windrows simultaneously at transversely spaced locations behind the head. Whether one or two windrows are laid depends, of course, on the thickness of the crop. It is preferably to be able to lay a windrow at a location spaced from either end of the head so that the outside windrow is not laid at the very edge of the field on the first swath, or the inside windrow is not laid against the uncut crop so as to interfere with the next swath. Also if the windrow from a swather head mounted in front of the tractor is delivered centrally of the width of the head, the window can be disturbed or damaged by the tractor which is conventionally mounted substantially on the centre-line of the swather, particularly if the crop is one, such as canola which leaves a very bulky windrow.